The architectural plan of the Qutub Minar is characterised by an alternation of which two geometric forms?

The correct option is Polygonal and Circular.

Explanation

The Qutub Minar is a quintessential example of early Indo-Islamic architecture, specifically the Mamluk style. Its construction was initiated by Qutb-ud-din Aibak and continued by Iltutmish. The tower is renowned for its tapering shaft and intricate vertical fluting.

Architectural Analysis:

• The plan of the Qutub Minar varies across its different storeys, creating a distinct visual rhythm.
• The first storey (the lowest section) is designed with an alternation of round (circular) and angular (polygonal) flutings.
• The second storey features only round flutings.
• The third storey consists exclusively of angular flutings.
• This geometric variation serves both aesthetic purposes, by creating a play of light and shadow, and structural functions.

Key Takeaway: The architectural plan of the Qutub Minar's base storey is characterized by the alternating arrangement of circular and polygonal geometric forms.